Originally Posted by rcf22
There are options in every ripping program to set the bitrate at which you encode it. Most audio enthusiasts here prefer a lossless codec, but if you choose to go m4a or something, be sure to encode AT LEAST at 128kbps, I prefer 192kbps.
I'm guessing that with M4A you mean AAC-LC... in my opinion, any more than 90-100kbps is overkill for most songs.
I encode with Nero AAC encoder at q0.3 which is 80-110kbps and between a 320kbps CBR MP3 rip and this, there is no noticeable difference. (there probably is a small difference, though it's impossible to tell because you can't compare audio like you can an image)
192kbps minimum for mp3, but for AAC-LC (not AAC-HE which sacrifices sound quality for compressibility), 90-100kbps is enough.